Dynamic electrical impedance imaging of binary-mixture fields with external and internal electrodes

Abstract

In the conventional electrical impedance tomography (EIT), the internal impedivity distribution, that is mixture distribution, is reconstructed based on the physical relationship between the known sets of injected currents through the electrodes and induced voltages on the surface of the domain of interest under the assumpution that the domain is stationary during the measurements. This study considers a dynamic electrical impedance imaging to binary-mixture systems with known internal structures to which additional electrodes can be attached. We attempt the utilization of the additional electrodes to enhance the recontruction. Also, we assume the domain is undergoing rapid transient, so the resistivity distribution in the domain of interest changes rapidly within the time taken to acquire a full set of independent measurement data. The dynamic EIT problem is treated as the nonlinear state estimation problem and the unknown state (resistivity) is estimated with the aid of extended Kalman filter in a minimum mean square error sense. Computer simulations for the two-dimensional object with abrupt changing resistivity distribution are provided to illustrate the reconstruction performance of the proposed algorithm.

Electrical impedance tomography with non-stationary electrodes

“…Internal electrodes, which are enclosed by the imaged domain, have been previously utilized to increase measurement sensitivity for medical, geophysics and industrial process applications. The concept of attaching electrodes to a central impeller is not new (see Lyon and Oakley (1993), Heikkinen et al (2001) and Kim et al (2004)) but a common theme amongst previous work is that the central (or internal) electrodes are either attached to a stationary sleeve positioned around the impeller shaft or modelled using numerical simulations only. The results from the previous investigations suggest that internal electrodes offer improved measurement sensitivity to conductivity changes in the central regions of the domain which in turn leads to some advantage in assessing the performance of process mixing.…”